Musically inclined kids are likely to start young on pots, pans and toy instruments, but what to do when they graduate to the real thing? Small space dwellers might have to shut down junior's wish for a double bass, but there are plenty of real instruments that don't take up a ton of room or cost a fortune. Secondhand is always our first choice, but when buying new here are ten of our favorites that aren't too big or too spendy.